This invention relates to heat exchangers and more particularly to isolation mounting arrangements of serpentine tube heat exchangers.
Vehicles commonly use serpentine tube heat exchangers as heat coils, condenser coils, and oil coolers. A serpentine tube heat exchanger is conventionally secured to a support rack. One means of supporting the serpentine tube heat exchanger to the support rack is to use a flat washer, cap screw and nut to clamp the tube loops to the support rack. Because the tube material, generally aluminum, is not sufficient to withstand high cap screw torque, the screw works loose under vibration causing fretting and eventual failure of the tube. Another method of securing the serpentine tube to a support rack is to place a spool between the loops of the tube and weld the spool in the flange area to the tubes. However, many times this weld is not sufficient to withstand vibration, causing the tube to break loose from the spool. Thus, the spool is free to fret causing failure of the tube. In cases where the weld is sufficient to maintain the bond, apparently the heat required to form the weld causes the tube to become brittle and vibration causes the tube to crack.
The present invention provides a means for mounting a serpentine tube heat exchanger to a support rack which does not degrade the heat exchanger material and minimizes the effect of vibration.